Twenty-seven male Bangladeshis working here have been arrested under the Internal Security Act.
Investigations showed that they supported the armed jihad ideology of terrorist groups such as Al-Qaeda and the Islamic State in Iraq and Syria (ISIS).
Some of them had considered waging armed jihad overseas but they were not planning any terrorist attacks in Singapore, said the Ministry of Home Affairs (MHA) yesterday.
The men, who were working in the construction industry here, were detained between Nov 16 and Dec 1 last year.
Of the 27, 26 were members of a closed religious study group that subscribed to extremist beliefs and teachings of radical figures like Anwar al-Awlaki, an American and Yemeni Islamic lecturer alleged to have ties with militant group Al-Qaeda. He was killed in a drone strike in Yemen in September 2011.
The remaining man was not a member of the study group but was discovered to have been undergoing radicalisation. He supported extremist preachers and possessed jihad-related material.
All 27 have had their work passes cancelled and 26 of them have since been repatriated to Bangladesh, where the authorities were informed of the circumstances of their repatriation.
The last person is now in prison for attempting to leave Singapore illegally after learning of his fellow members' arrests. He will also be repatriated once he completes his sentence.
In the course of their arrests, the Internal Security Department recovered a "significant amount" of radical and jihad-related material, such as books and videos containing footage of children undergoing training in what appeared to be terrorist military camps.
Some members possessed a shared document with graphic images and instruction details on how to conduct "silent killings" using different methods and weapons.
The group members took measures to avoid detection by the authorities, sharing jihad-related materials discreetly and holding weekly gatherings to discuss armed conflicts involving Muslims, said MHA.
"They also carefully targeted the recruitment of other Bangladeshi nationals to grow their membership," it added.
A number of members contemplated travelling to the Middle East to take part in the ongoing conflict.
"Foreigners are guests of our country and they should not abuse this privilege and use Singapore as a base to import their own domestic political agenda and carry out activities in pursuit of such an agenda," MHA said.
"Foreign religious speakers who propagate divisive doctrines which could lead to mistrust, enmity and hatred among local religious groups and undermine Singapore's social cohesion are not welcome and will not be allowed to operate in Singapore."
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